Disaster Report 4 is the latest entry in Irem's disaster survival series, and like its predecessors it kicks off right as your city is struck by a major calamity.

But here's one totally new element. In previous entries in the series, once you cleared one map and moved on to the next one, you'd never return to the previous map. That's changed for part 4.

As detailed at Famitsu.com, the game's story will take you back to past areas. You'll see some changes, as shown in the following example.

Early in the game, immediately following the earthquake that destroys the city, a fire will break out in a high end shop. Here's what it looks like:

And here's the same area when the main character visits later.

The fire has been put out, and you'll be able to enter the remains of the building and search for items.

It looks like you also may see some differences due to being in the same area at a different time of day:

In the second set, a fire that had engulfed a train has been cleared out and workers are working to restore transportation. With all the construction lights, perhaps you can now pass through the street?

Disaster Report 4 is still without a final release date. The game is currently flagged by Irem as Spring 2011.